The blog post on the Microsoft Jobs website read: "Do you already know everything about Project Natal and the Cloud?..Then check out some of the online chatter surrounding new releases of Windows Phone 7 Series handsets, Internet Explorer 9 and the forthcoming Courier digital journal."

The mention of the Courier has since been removed from the blog post. Microsoft said it would not comment on rumour and speculation surrounding the Courier.

The slip comes just days after a senior Microsoft executive mentioned the Courier on Twitter. Stefan Weitz, a director on Microsoft's Bing search team, tweeted a link to an Engadget report about the Courier with the message: "Welcome to the epic. New shots of our new Courier product".

Rumours about the Courier – a dual-screen, tablet computer – have swirled online for months. Microsoft is said to have set up a secret division of engineers and hardware and software experts to work on the device, which could rival Apple's forthcoming iPad.

According to reports on Engadget, the Courier will go on sale towards the end of this year, and runs the Tegra 2 operating system the powers the Zune HD.